coltish

Etymology

From Middle English coltyssh, equivalent to colt + -ish.

adj

1. Resembling a colt, especially:
   1. Lively, playful and undisciplined (often in a manner judged to be immature).
      Commeth he in the morning to do his dutie and bid thee good morrow, belching sowre and smelling strongly of wine, which the day before he drunke at the taverne with companions like himselfe? seeme to know nothing. Senteth he of sweete perfumes and costly pomanders? Hold thy peace and say nothing. These are the means to tame and breake a wilde and coltish youth. 1603, “The Education of Children”, in Philemon Holland, transl., The Philosophie, commonlie called, the Morals written by the learned philosopher Plutarch of Chæronea, London, page 16
      Plants rais’d with tenderness are seldom strong, Man’s coltish disposition asks the thong [i.e. whip], And without discipline the fav’rite child, Like a neglected forrester runs wild. 1782, William Cowper, “The Progress of Error”, in Poems,, London: J. Johnson, page 59
      […] the batsmen were running and stretching bats, and the ball flying away, flying back, and others after it, and still the batsmen running, till it seemed that the ball had escaped control and was leading the fielders on a coltish innings of its own, defiant of bowlers. 1885, George Meredith, chapter 12, in Diana of the Crossways, volume 3, London: Chapman & Hall, pages 231–232
   2. Tall, thin and awkward (especially of an older child or adolescent).
      He had a tangle of shock hair, the colour of wool; his mouth was a grin; although as strong as a horse, he looked neither heavy nor yet adroit, only leggy, coltish, and in the road. 1883, Robert Louis Stevenson, “The Hunter’s Family”, in The Silverado Squatters, London: Chatto & Windus, page 138
      ‘Darling boy, how are you?’ she said. ‘Do you know, you’re beginning to look rather lovely in a coltish kind of way. Don’t you think so, Otto?’ 1928, Evelyn Waugh, chapter 3, in Decline and Fall, London: Chapman & Hall